Finned tube



Petented May 24, 1938 UNITED STATE FINNED TUBE R. Harry Stone, BoundBrook, am! Edwin F. Tilley, Dunellen, N. J., assignors to Titeflex MetalHose 00., a corporation of New Jersey Original application July 26,1930, Serial N0.

Divided a.nd this application Octobei 4, 1933, Serial N0. 692,088.Renewed Allgust 24, 1937- 8 Claims. (GI. 257262) This lnvention relatesto tubes and has special referenee to the transfer of heat to or fromthe seme. 1

The pisent appllcation is a dlvlsion of nur application Serial Number471,034, filed July 26, 1930 which has since matured into Patent N0..1941587 dated January 2, 1934.

'Ihe mein object of the invention is to provide improved means foreffectingyfiransfer of heat to -or from the tube--from the taube when itis desired to dlsslpate heat from the contents of the tube as is thecase with radlators heaters and the like, and from the surroundingmedium to vention to provide the improved heat exchanging means incormection with a corrugated taube.

It is a f1'1rther and ancillary object of the inven- .tion toprovide-a;he'at transferring fin inconnection with a corrugated taube.

It is a further object of the inventionto a heat transferrlng fin inconnection with a corrugatedisube formed from a grooved st rip hellcallydisposed and having the edges of adjacent convolutions secured togetherwhereby the canstruction and processes of manufacture are greatlylmproved.

A further and 4ancillary object of the inventlon is to provlde animproved constructioh of finned tube.

Other and a ncillary objects of the invention will appear herelnafter.

In the accompanying drawlng which illustrates the invention- Fig. 1 lsa. v1ew, partly in slde elevation and partly in section, of a structureof corrugated tube embodying the inventlon;

Fig. 2 is a viewpartly in elevation and partly in section, 01 a modifiedform of tube'embodying the invention;

Fig. 3 is a vlew, partly in side elevation and partly in section, of astill further modified structure of taube embodying the invention;

Fig. 4 is a view, partly in side elevation and partly in section, of astill further modified structure of taube embodylng the lnvention; und.

Flg. 5 is a view, partly in side elevatlon am]. partly in sectlon, of a.still further modlfled structure of tube embodying the inventlon.

F-eferring tq the drawing, and first to Fig. 1, there is therein showna. corrugated tube wlth the heat exchange fln mounted upon the outers1de of the corrugation. The efliclency 01 the taube a.s' a

Drovide heat exchanger may be very greatly increased by combining thecorrugation with a fin upouthe outslde thereof over what could beaccomplished with either the corrugation or the fin alone. Thecorrugation increases the radiating surface of the tube exposed to theair and so increases its radiation. Upon making the corrugations toohigh, however, the pocketing 015 air between the corrugations is verylargely lncreased so that there is more eflicient radiation if thecorrugations are made of moderate depth and a fin of heat-conductingmate'rial is supplied on the outside' of the corrugation. Also the usecf the corrugation in combination with the fin on its outside is moreefficientthan depending upon the height pf the corrugation to give thedesinad. heat exchange, for the reason that if the corrugation is ma.detoo hlgh the heated fluid in bassing thr0ugh the tube is apt to notpenetrate into the extreme recesses of the corrugations so thatradiatlon from the outer surface of the corrugation 1s impaired, whereasif the corrugation is'made low the heated fluid within it penetratesfully throughout the corrugation and delivers 1cs heat thereto, the finat the outslde'of the corrugation a.ctlng 1:0 conduct awajy such heatand dissipate it into the surroundln'g atmosphere. -Also it is desiredto limlt the helght 01 the corrugation and combine it wlth a. fin asdescribed, because a corrugation of too gre.t height, under somecircumstances, too greatly retards the flow of heated fluid through thetaube; v

In Flg. 1 the strueture includes a tube formed from a helically disposedstrip of metal having the edges cf adjacent convolutions interfolded asin the patent of the United Staates of America to Louis H. Brinkman N0.1,198,392 patented September 12, 1916, and having the corrugations 56,the fin being .provided by a helically disposed metal strip having -aright-angled section comprising the radial portion 51 and the footportion the groove between the corrugations and does not flow freelyaway so that the radiation or dissipation cf the hea.t Irom the tube isimpa'ired. Thls. conditlon may be greatly improved and the corrugatedtube as a radlator ofheat may be improved, by placing a metal or otherheat conducting fin within the space between the corrugatlons. Thisconducts the heat away from lts confined space and largely lncreases theheat radlatlng capacity of the tube by relievlng the congestion of heatwhich occurs in the space between the cor'- rugations.

A device embodying this conception is shown in Fig. 2 of the drawing,wherein the corrugated tube 43 is formed by helicallydi'sposing a metalstrip hav ing a longitudinal groove and. interfolding the edges ofadjacent convolutions as described in the Brinkman patent hereinbeforereferred to. This tube has the corrugations 44. Between the corrugationsis a. helically wound strip of metal having a cross section comprlsingthe radially extending fin 45 and foot 46 at right angles thereto. Thestrip last referred to is wound helically within the groove of the tube43 between the corrugations 44, and the foot 46 rests upon the tube 43between the corrugations. The strip comprising the fin 45 and foot 46may be secured 130 the tube 43 by soldering, welding or in othersuitable ways, or it may be unsecured. to the tube 43 merely restingagainst it.

It will be seen that the fin 45 of the strip couducts the heat of thepocketed air between the corrugations outwardly and dissipates it; also,the strip, including the fin 45 and the foot 46, being in contact withthe tube 43, will act to directly eonduct the heat from the tubeoutwardly, which further fact improves the radiation because heated airbeing pocketed between the corrugations, the tube between thecorrugations does not so readily radiateits heat.

In Fig. 3 is'shown a modified construction 01 tube havlng a radiatingfin between its corrugations, the corrugated tube being shown, like thatin Fig. 2, as being the same as shown in the Brinkman patenthereinbefore referred to. The fin 48, however, instead of being formedof a helical strip 015 angular cross section, is formed 01 a flat striphelically wol'md in the groove between the corrugations of the tube 41.The fin or strip 48 facilitates the dissipation of heat from between thecorrugations as already explained in connection with the device of Fig.2 and may be soldered, welded, or otherwlse secured to the tube or maysimply lie upon lt as it is wound thereon.

In Fig. 4 is shown, partly in side elevation and partly in section, acorrugated tube whlch is integrally formed instead of being formed of astrip as hereinbefore referred to. This integrally formed corrugatedtube has a fin 64 located between the corrugations 65. This fin isformed of a helical strip of metal or other suitable beatconductingmaterial. This strip may be welded, brazed, soldered or otherwisesuitably secured to the tube, or itmay simply lie in contact therewith.

In Fig. 5 is shown an integrally formed corrugated tube having a helicalstrip of metal or other suitable heat-conducting material secured to theouter side of the corrugation by soldering, brazing, welding or in anyother suitable way, this strip forming a hea.t radiating fln incouiunction with the corrugation.

Whlle the invention has been illustrated in what are considered its bestapplications, it may have other embodiments without departing from itssplrit and is not therefore limited to the structures shown in thedrawing.

What we claim is:

1. The combination with a helically corrugated tube, of a separate striphelically disposed about said tube and secured thereto at its inneredge,

said strip being between the Corrugations of said tube and comprisingflat portions of different cross sectional dimensions at right angles toeach other, the greater of said dimensions extending radially of theaxis of the tube.

3. The combination with a corrugated tube, of a separate strip helicallydisposed with relatlon to the axis of said tube and secured thereto.said strip being mounted ab the unter end of the corrugation.

4. The combination with a tube formed of a helically disposed striphaving the edges of adjacent convolutions secured together in a fixedjolnt and a heat-conducting fin secured in said jolnt and extendingoutwardly therefrom.

5. The combination with a corrugated tube comprislng a helicallydisposed strip having a longitudinally extending groove forming asorrugation in the completed tube, the edges of adjacent convolutionsbeing secured together in a fixed joint, of a helically disposedheat-conducting fin entering in said joint and projecting outwardly,said joint being at the outer surface of the corrugation.

6. The combination with a corrugated tube, 015 a helically disposedstrip having an angled section, one of the legs 0f said section beingsecured. to said tube and the other leg projectin'g outwardly.

7. The combination with a corrugatecl tube comprlslng a.helically'disposed strip having a longitudinal groove forming acorrugation in the completed tube, and the edges of adjacentConvolutlons of the strip being interfolde'd to form a joint between theconvolutions, of a helically disposed strip having a right-angledsection, one of the legs of the angle being inserted in said joint andthe other leg of said angle projecting outwardly.

8. The combination with a corrugated tube comprising a helicallydisposed strip having a longitudinal groove forming a corrugation in thecompleted tube, and the edges, of adjacent Convolutions of the stripbeing interfolded to form a joint between the convolutions, of ahelically disposed. strip havinga right-angled section, one cf the legsof the angle being inserted in said joint and the other leg of saidangle projecting outwardly said joint being at the outer end of thecorrugation.

EDWIN F. TILLEY. R. HARRY STONE.

